Studying the Impact of Weather Conditions and Operating Modes on the Thermal State of the Primary Voltage Converter of a 110 kV Digital Transformer

Abstract

Instrument current and voltage transformers play an important role in the reliable operation of electrical power systems and networks. This study examines heat exchange between the primary voltage converter of a 110 kV digital transformer and its environment, taking into account such unfavorable factors as high ambient temperatures, windless conditions, intensive insolation, and excessive grid voltage. Mathematical simulation and numerical study of temperature fields in primary converter components were performed. To define this task, a differential thermal conductivity equation was used taking into account heat release in conducting parts, which was resolved in a complex computational domain together with boundary conditions, taking into account interaction with the environment (convective and radiant heat exchange). This task was fulfilled with the aid of specialized software. The mathematical model was verified using a physical experiment. The components most subjected to heating were determined and the dependence of maximum temperatures on determining parameters (voltage, ambient temperature, insolation, and others) was showed. This study, featuring analysis of transformer converter thermal state, is essential for the further development of algorithms relating to thermal self-diagnostics of transformers that will be used to ensure reliable operation of electric power systems and networks.